The present invention relates to an omnidirectional vehicle having at least three wheels which can be steered so that the vehicle can travel in any direction.
Conventional vehicles with wheels are classified into two categories: automobile type vehicles, whose front or rear wheels are steered to change the direction in which vehicles travel, and omnidirectional vehicles, whose wheels are all steered in a certain direction so that the vehicle can travel forward, backward, right, left, or diagonally without changing the vehicle position. The conventional automobile type vehicle has a larger turning radius. Since the omnidirectional vehicle can change direction without changing vehicle position or orientation, it is used in, for example, office robots, which must change direction and travel in the narrow spaces between desks, and other vehicle, which must make sharp turns in accordance with a complicated pattern.
A conventional omnidirectional vehicle can change direction by steering a plurality of wheels by independent steering mechanisms using special drive sources.
The conventional omnidirectional vehicle of this type has a steering motor for each wheel and is thus expensive. Since all the wheels must be simultaneously steered in a given direction, the steering motors must be synchronized. Synchronizing control devices are complicated and expensive.
Another conventional omnidirectional four-wheel vehicle has been proposed. This vehicle has a first pair of wheels interlocked for direction change, a second pair of wheels similarly interlocked for direction change, and two steering mechanisms for steering the first and second pairs of wheels. This type of omnidirectional vehicle requires two steering motors and two interlocked steering mechanisms for interlocking the first and second pairs of wheels. Therefore, vehicle cost cannot be greatly reduced. Even in this kind of omnidirectional vehicle, the control device for synchronizing the two steering motors is complicated and expensive.